Improve printing of GPS info

[kmilos]

Addresses #1541

[clanmills]

Thanks, Milos. That looks fine. Thank You for dealing with this.

[clanmills]

This looks good. A few comments:

1 Converting rationalToFloat()

I'm a little surprised that so much code is necessary in printDegrees(). Is there a lesson to be learned here. There is a API:

EXIV2API Rational floatToRationalCast(float f);

I thought there are one to convert rationalToFloat(), or Long, or Double. I can't find it. Is there something special and unusual about degrees() such as doing arithmetic on several values.

2. Is the result the same as ExifTool?

3. Well spotted that I put "knots" in the man page. It should of course be nautical miles.

[kmilos]

Is there something special and unusual about degrees() such as doing arithmetic on several values.

There are two ways of lat/lon encoding w/ 3 RATIONALs according to Exif spec: integer degrees and minutes and then anything goes for seconds (integer or fractional) like [ DD/1, MM/1, SS/1 or SSSS/frac], or fractional minutes with seconds "unused" [ DD/1, MMMM/frac, 0/1 ]. We need to convert the second case (I chose to make it fit the first one), and then print consistently in the usual degree/minute/second format...

Is the result the same as ExifTool?

One exception: ExifTool prints .00" even when seconds are integers...

[clanmills]

Right. You've got your head round this one. That cosmetic difference with ExifTool seems OK to me. I'm happy for you to merge.

[clanmills]

Let's agree on a team convention. The person who opens a PR also does the merge. Why? Because if you suddenly think of a modification to the PR, you can update it before merging.

[kmilos]

Thanks. Fine by me.